GS Renovation builds rear, side and wraparound extensions on houses in Rickmansworth. We appoint the structural engineer, build to their calculations, and coordinate the building control application and inspections from the foundations up. Fully insured, registered in England, company number 14611254, with free no obligation quotations and one point of contact on site.
Which authority decides, and under which plan
The local planning authority for Rickmansworth is Three Rivers District Council, and planning enquiries go to 01923 776611 or dc.online@threerivers.gov.uk. The Batchworth Neighbourhood Plan 2023 to 2038 was made on 20 May 2025 and now forms part of the development plan used to decide planning applications in the area. It covers Eastbury, Moor Park and Rickmansworth within the Batchworth Community Council parish boundaries.
Policy BW DE1 of that plan requires new development to respond to the Batchworth Neighbourhood Design Code on building heights, materials, development frontages, plot widths, boundary treatments and street enclosure, and states that departures need full justification. A design that ignores the code is therefore not simply a question of taste. We are a contractor and not a planning consultant, so on anything borderline we would expect you to take architectural or planning advice before an application goes in.
The design code has its own checklist for extensions
It asks specific questions, and they are worth reading before anything is drawn. The household extensions checklist in the Batchworth Neighbourhood Design Code asks whether the roof form of the extension is appropriate to the original dwelling, taking account of the angle of pitch. It asks whether a side extension retains important gaps within the street scene and avoids a terracing effect, and whether it is set back from the front of the house.
It also asks whether dormer roof extensions sit within the roof slope. On materials, the code states that alterations to existing buildings must use local materials, and that artificial materials imitating traditional ones should be avoided. It names yellow stock brick, red brick and white render as the building materials of the plan area. Matching brick and mortar to the original house is a sourcing decision we make early, because lead times on a genuine match run longer than people expect.
Moor Park sets measurable numbers, not just principles
The appraisal there gives figures you can check a sketch against. A minimum of 20 per cent of the site frontage at existing building lines must be kept clear of all development along the entire flank elevations. Not less than 1.5 metres is to be kept clear between flank walls and plot boundaries. Buildings including all outbuildings such as garages and car ports should not cover more than 15 per cent of the plot area.
That 15 per cent counts any first floor area overhanging the ground floor and any basement area built beyond the ground floor footprint. Construction in front of the existing building line or facade is unacceptable, and that includes replacement garages and porches over specified dimensions. The appraisal also states that flat roofs, and flat sections formed by truncating a pitched roof with an artificial ridge, are unacceptable in the conservation area. Those constraints shape the design before costing begins.
Ground conditions and the forms that go with an application
Foundations are designed to what is actually under the plot. British Geological Survey 1:50,000 mapping records the bedrock beneath Rickmansworth High Street and Station Road as the Lewes Nodular Chalk Formation. It records Alluvium, described as clay, silt, sand and gravel, over the chalk on the valley floor at the Rickmansworth Aquadrome, at Batchworth Lock and along the lower part of Cedars Avenue. Around Sandy Lodge Road in Moor Park the bedrock is the Lambeth Group, and under Main Avenue it is the Seaford Chalk Formation.
On paperwork, Three Rivers District Council requires a local biodiversity checklist with planning applications, alongside the application form and location plan, plus a Community Infrastructure Levy additional information form. The whole Batchworth plan area falls within a Mineral Safeguarding Area, so applications for non minerals development may not be determined until Hertfordshire County Council has had the chance to comment on whether the proposals would sterilise mineral resources. Build that into your expected decision time.
- Party Wall Act notices for excavation near a neighbour's wall
- Planning applications and permitted development assessments
- Architectural drawings and structural engineer coordination
- Bi-fold, sliding and French door openings to the garden
- Brickwork and mortar matched to the existing elevation
Why Choose GS Renovation in Rickmansworth
An extension here is judged against the Batchworth Neighbourhood Plan and its design code, which became part of the development plan in May 2025, and departures from the code need full justification. GS Renovation builds to the engineer's calculations, coordinates building control from foundations to completion, and tells you where the design questions need an architect or planning consultant rather than a contractor. One point of contact on site throughout.
- Garden levels and access made good where the build meets outside
- Permitted development checked before you pay for a planning application
- Straight advice on what is and is not worth spending money on
- Scaffolding and site set-up planned for tight London plots
- Free, no-obligation quotations
- Building control applications and inspections coordinated for you